Pulsation absorber



Aug. 7, 1951 E. w. LOUKONEN PULSATION ABSORBER Filed Sept. 16, 1946 INVENTOR ERNEST W.LOUKONEN ATTORNEY Patented Aug. 7, 1951 UNITED STATES PATENT OFFICE .PULSATIO BS RBER I s H Ernest-W.'Loukonen, Long Beach, Ga 1if. A pli ation S ptember 16, with rial o- 97 319 y nvent o e ates. t e! pu sat n o ber;

h e a at vely hiehpres e isflrequi ed, or I a at v large o um f. fluid. is, splace u ne eh troke oth pum pist ns. theul s ls iens n t e s stem cause un es d iie s h a creatin bra i n nthe s stem esu n n am g o ipe hose r h r. c n-f dui s m loyed to con uet e h d a l luid. and p n ndesi a le n unne es ary tra ns upo va ou p eces i appar ein pl yed in the stem, 7

One s tem o seher et r is the. y rauli t m employed f ircii tin i uid. h ou ha stri eof drill p ed rih thez tilling i ep wells in which the circulating fluid ispassed down throu h the st n 9i d il pipe .f r, th 191111- pQse of wash n out ehe rem v the. cu t n s medeh the i nsii hs t ms his he om: mon practiceto interconnect the stringof driii pipe with the ci cula on pumnbymeehse ei h flex le ho es o oi ted. pip s h eu h ich the fluid is. sse from. t e pi m o e. dr ll rin prop I In many. nstances, th ressiires h eh ret re ui d o be em loy d .feri'the ircu ating flu d re xtreme hi hi hdthe ulsat o s o the pump e et e smitted. h h he flexib e pipe o s to h up ei". end i. thedril s rin ul s n hd s ed'ehd dan ero s v t n of the upper end i he. 11' 'E4iIi .t e revel n block n es f he mist ng s stem emplo ed to suspend the driil string during the drilling operijions, s on. s be ev hereteip ehe n sed that-are complicated in construction @nd reguire periodic bleeding. When 'oiibecomes mixed with the air in such absorbers-an explosive mixture is formed which is dangerous, particularly on bleeding. plished byunScrewing-a plug whichiorms a den: gerous projectile where high gas pressures-are pr n ins eh' s rbe s. Ith e f e ieet: 9i." inve tion to.

Further, bleeding is often aocomw system su p ied b hep mp.

Another object -Q. .,.m inven on is e ie i e a pul a i n ehsorh h l yiee wh h is. im in sIcoh t u iQ and ieis ehsi e e .m hhiett ie; and which doesn t requi e leedine- 1 It i als n object oim n e tio to ro de a p l at on abso b r. wh h .e ris s a hamber iv ed in two ertsyb means. of. lexible i hra m he eit be n c mu ica ed. h he disc e oitherecipr e he p m and the th r part e n fi l d with as r ir at eipres u suhstent lye eet rtheilietmo heri t a d tiona hieet. i m hv hlto p ov de a .de i ee the .s re'e er et orth in the pi ee ne ara ph 11!..Whi9h. he nneetioh means ier attachment to he. disch rg lihept he umpiheludes a. o t n. oi, arge d meter to fiec iv y. du e heve p i y ofiiew of fluid nto and u oi. he chem r- Another b ct r. m inventi n s o roy ie him py cl iaph a m const uct on iorepul: etip ab rber wh ir hthe d hifaehi is. net nder a stret h 0. 'hsionload. w A still her. ticket o m nven ion o pro an mproveddianh e m r a u at n ebs e t tel eets as, a. al for h atin urfa s of h t o rt formin a. m er, n which the. diephregrnacts. ti a urther obiee he n n ion isto pr v deen m v est pl e or limiting he movement he e h e m' hd the influence a o re sib m diu O er b ct ndedv n es of my in nt on will be apparcnt f rom a studyof the following pec a ions, r ad n; c ct n; h the ccompehyih draw n s; he in Fig. 1-is a side elevational view illustrating the form and appearance ofthe preferred embodi: ment of my invention; Fig. .2 is a longitudinal sectional view-taken through the device'shown-in-Fig. 1;; and.

Fig. 3'is a topvie'w of the pulsation absorber of Figs. 1 andz. Referring to the drawings the pulsation absorber of my invention may be. connected to the ou put ne 0 he pump rev ous m nt ned; for example, mud pumps as used i the oil. in: s r h se i put ,line ma nclude. w pi e et iehs. Ill and threedediht e1" c nnect on 121.. o h ch st e hect d t p lsetie o be 3 of my invention indicated generally by the reference numeral I4.

The main portion of the pulsation absorber housing may be formed by two shell members, a lower, generally funnel-shaped member I3, and an upper, generally dome-shaped member I6. The lower, funnel-shaped member I3 may have its smaller end formed with pipe threads I! for engagement with the T connection I2, and may have machine threads I8 formed on the outer surface of the larger end. The funnel-shaped member I3 is preferably formed of cast metal, and during this casting operation may have integrally formed thereon an hexagonal portion I9 for engagement by a wrench for threading the member into the T connection I2. The larger end of the funnel-shaped member I3 may be interiorly relieved to form a recess having an annular shoulder 2 I.

The upper housing member I6 has its interior surface generally rounded in substantially parabolic dome-shaped contour and has its open end interiorly relieved to form an annular recess having a shoulder 22 similar in size and extent to annular shoulder 2 I. The open end of the dome I6 is also formed with an external annular shoulder 23. The dome member I6 is preferably formed by casting, and during this operation four projecting bosses may be formed thereon including two smaller bosses 24 and two larger bosses 26. The smaller bosses 24 may be drilled as at 21 to communicate with the interior of the housing I6. A guage fitting 28 may be threaded into one of the bosses 24, and a pressure guage 29 secured thereto. Also a gas valve unit 3I may be secured to the guage fitting 28 or to the other boss 24, as desired. If either passage 21 is not utilized in one fashion or another, it may be closed as by a plug 32. The larger bosses 26 are not drilled through to the interior of the housing I 6, but are drilled a short distance and then tapped for receiving handles 36 shown in broken outline in Fig. 3. These handles may be of suflicient length to. form a convenient hand grasp for lifting and moving about the dome member I6 or the entire pulsation absorber when it is assembled. The dome member -I6 and the funnel-shaped member I3 define a pulsation chamber 25.

The two housing members I 3 and I6 may be securedtogether particularly in accordance with my invention by means of a locking ring 33 having an internal flange 34 on one end to contact the external shoulder 23 of the housing member I6; A cylindrical portion 36 of the locking ring 33 closely fits about the outer periphery of the dome member I6, and a further enlarged portion is internally threaded as at 31 to engage the threads I8 on the lower-funnel-shaped member I3. The locking ring 33 is also preferably cast, and during the casting operation a plurality of spaced lugs 38 may be formed on the external surface thereof for engagement by a wrench or other device for threading the ring onto the funnelshaped housing member I3. Y

I provide the pulsation absorber with a'flexible diaphragm 38 made particularly in accordance with my invention and which may have a general bag shape such as a hemispherical shape with the edges thereof formed with a double flange 39. The diaphragm 38 is preferably molded, and I have found that some of the synthetic rubbers such as neoprene are quite satisfactory. The diaphragm is positioned within the housing members I3 and I6 by means of two rings 4I and 42 placed inside either edge of the double flange 39 of the diaphragm 38. Accordingly the ring- 4| may rest upon the shoulder 2I and the ring 42 may rest upon the shoulder 22 when the entire pulsation absorber is assembled. The effect of the rings 4| and 42 is to align the double flange 39 so that it is generally cylindrical. Further, it will be noted that the edges of the rings 4I and 42, which may be made of steel, are rounded where they contact the diaphragm 38 in the region; of the double flange 39. I V

In order that pulsations in the fluid delivery pipes I0 and II may be absorbed, a gas under pressure, such as nitrogen, may be inserted through the valve 3I to fill the entire interior of the housings I3 and I6. This gas pressure urges the diaphragm 38 downwardly, and to arrest its movement ina' downward direction I provide a perforated plate 43. This plate preferably rests in an annular groove 44 formed in the interior of the funnel-shaped housing member I3, and for the greatest strength; prefer to cup or dish the perforated plate 43, so that when it receives the forces due to the gaseous pressure in the housing, it will tend to expand against the housing I3, which housing being relatively inelastic, will prevent a further deformation and the entire dished plate 43 will act as'an arch. .The dished structure of the plate 43 also provides a greater area for perforations therethrough than would be the case with a flat plate. I design the diaphragm 38 of my invention of sufli'cient size with respect to the position of the perforated plate 43 so that when the diaphragm is fully extended, as shown in Fig. 2, it is not in a stretched or otherwise stressed condition. Similarly, the size of the interior of the dome member I6 is so designed with respect to the'portion of the lower housing I3 above theplate 43 asto be approximately the same size, so that when abnormal liquid pressures force the diaphragm into the upper dome member I6 it will not be stressed even though nearly all the air should be compressed or released from the dome I6 through leakage, improper servicing, etc. Accordingly, therefore, the diaphragm 38 is never stressed, since during operation the gas pressure will equal the liquid pressure, and when all liquid is excluded the diaphragm will rest upon the plate 43 as shown in Fig. 2. This lack of stress materiallylengthens the life of the diaphragm 38 in operation. Alternatively, or in combination with the perforations of plate 43, the edges may be milled as at 45 to permit liquid flow.

In assembling the pulsation absorber I4 of my invention, the lower housing member I3 may be positioned in any suitable manner, and the perforated plate 43 placed therein. The plate may thereafter be tapped with a hammer or otherwise deformed to have a friction engagement with the notch 44 in which it is seated. The rings H, and 42 may then bepositioned against the double flange 39 of the diaphragm",v and the assembly of the diaphragms38and the, rings H and 42 may then be placed within the lower housing I3 and theassembly may come to rest upon the shoulder 2I .in the housing member I3. Dowel pins 46 may next be threaded in the lower housing member I3 so that they project upwardly from the upper surface of the housing member I3. The dome I6 maynext be placed upon the assembly of the diaphragm 38 in the lower housing member I3, and may be handled by grasping the pipe handles 30 as shown in Fig. 3. The dome member I6 may be positioned over the diaphragm assembly. until .the drilled holes 41 in the lower surface of the housing receive the projecting dowel pins 46. The lockingvringi 33 isrnext 'posie tioned" over the-dome shaped member l6 and threaded'into engagement-with the lower mem+ ber' I3 until the two housing members [3 and 16 are in tig-htcontactwith each other; This construction is such, also, that the contact is suffi'c'ient even though the locking ring 33 isthreaded by'hand. Thereafter the guage fitting 28;: the guage 29 and the gas valve-3l are'next assembled to the dome member I 6 and the unitis then complete.-

In operation the pulsation absorber M may be secured to any'sui-table" pump outlet as indicated by? the pipes l and H:in:Fig; l, andithe: unit may then be charged with agas, preferablysan inert gas'such as nitrogen, to a pressure commensurate with the pulsation pressures to be absorbed.v For example, ifthe pulsationsare on the; order of 5,000'p: s; i.', the absorberIn-ay be charged with nitrogen to" a pressure from 3,000 to,"4,000 p..s. i. The desired pressure and the peaks of pressure occurring during operation may be. observed upon the pressure, indicator 29. When pulsations of fluid pressure occur in the lines [0 and I I, the fluid will travel through the lowerportion of the funnel-shaped member 13 and into the diverging part. thereof, Where its velocity will be materially reduced because of the greater volume through, which the pulsation of fluid will move. If the fluid pulsation is of sufflcient pressure, the fluid will pass through the perforated plate 43 or through the notches 45 in the edge thereof, urging the diaphragm 38 upwardly against the compression of the gas on the other side of the diaphragm. As the diaphragm goes upwardly, the gas pressure thereupon will be increased, gradually reducing the velocity of the upward surge of the liquid pulsation. An equilibrium point will be reached where the pressures of the liquid and gas are equal. The ability of the pulsation absorber M to smooth out or alleviate these high pressure peaks from the line prevents ruptures of liquid conduits which would otherwise occur due to the hammer effect which may be magnified in any system dependent upon the connection thereto.

During the operation of the pulsation absorber, the diaphragm will be flexed upwardly and downwardly as mentioned, but will be held securely in position at all times by the rings 4| and A2 holding the double flange 39 of the diaphragm in the respective recesses in the housing members l3 and I6. Inasmuch as no stretch is present in the diaphragm because of its shape, these rings perform this function without being subject to stress. The pressures of the liquid and gas acting on the double flange 39 force it outwardly, automatically sealing the joint between the housing halves. Thus the double flange 39 acts at all times as a seal for the joint between the housing members l3 and IS, the fluid pressures inside of the housing compressing the double flange 39 against the joint.

The pulsation absorber M is at present de signed for operation pressures on the order of 5,000 p. s. i., and accordingly is usually tested at 12,000 p. s. i. The material accordingly should be extremely rugged and shock-resistant. The housing member E3, the dome member l6 and the locking ring 33 accordingly are preferably made from cast steel, either carbon steel or alloy steel, and these castings are preferably annealed before machining. Various other materials may be used, however, according to the operating pressuressonwhichthezunitssmaycbesusedz .Theunate ingzsurfaceszof therhousing; members l3sianda l6 should Y be 1 accurately r finished: toinsure a good fit.- The-pulsation absorber'may be of any: de-: sired size, and I-h'ave' successfully .used pulsation absorbers having an overall. diameter of. about twelve inchesand an overall heigh't of about fourteen inches.

While :-I have described my invention with respect: to a single preferred embodiment-thereof, it is obvious that various modifications may-be made therein' without departing from the true spirit 'and'scopeof my-invent'ion'." 'F'o'r example; different shapes of housing members could be used, .and' different connections could be used without departingfrom the scope ofthe' inven-' tion. Accordingly I donot' careto limit myself to the specific embodiment; nor othe1-wise,fexcep t by the terms of the following claims. I-claim:

11- A pulsation absorber comprisinga funnelshaped housing member having pipe threads-on its smaller end and machine threads on the out side of its larger end and having anannular groove formed on the interior adjacent the'small end and having anannular recess formed at the interior of its'la'rgr enda dome-shaped housing member'adapted'to be -joined with'thelarge end of the funnel-shaped housing member and having an interior annular recess at its open end substantially of the same size as the recess on the funnel-shaped member, a bag-shaped diaphragm disposed within the two housing members and having a double flanged edge which automatically seals the diaphragm against loss of either gas or liquid, on either side of same, a ring contacting each portion of the double flanged edge of the diaphragm for holding the flange within the recesses of the two housing members, means defining a gas passage through said dome-shaped housing member and communicating with the interior thereof, a gas valve communicating with the passage in the domeshaped housing member, a dished plate disposed on the annular groove in the funnel-shaped housing member, and a threaded locking ring extending about said dome-shaped housing member and engaging the threads on the funnel-shaped housing member to secure the two housing members together.

2. A pulsation absorber comprising a funnelshaped housing member having an annular groove in the interior thereof, a dome-shaped housing member adapted to be joined to the large end of the funnel-shaped housing member, a bagshaped diaphragm secured between the two housing members, and a perforated arcuate plate resting within the annular groove of the funnelshaped housing member and dished away from the small end of the funnel-shaped member.

3. A pulsation absorber comprising a housing member having a funnel-shaped interior, a dome member having a substantially parabolic interior joined to the large end of the housing member to define therewith a chamber of diminishing cross section as it approaches the ends, a flexible diaphragm disposed across the chamber and secured at the junction of said members to divide the chamber into two portions, said diaphragm having an area such as to permit its contacting the entire inner surface of either portion of said chamber, and a perforated plate disposed across the small end of said funnel-shaped member dished inwardly of said chamber.

4. A pulsation absorber comprising a housing deflning a fluid chamber, said housing including a housing member and a dome member joined together, a diaphragm extending across said chamber and having a double flanged edge, a recess in each of said members at the line of junction of said members, said recesses each having a depth in excess of the thickness of said flange, and a ring in each of said members for engagement with said flanges, said rings each having a thickness equal to the excess depth of said recesses to provide a filling for said recesses and to present with the interior surface of said members a smooth continuous surface for con tact with said diaphragm.

5. A pulsation absorber comprising a two-piece housing joined together to define a fluid chamber, said housing comprising a pair of complementary members, each open in the plane of its largest diameter, a recess formed at the open edge of each of said housing members and extending circumferentially about the interior of said members, a diaphragm extending across said chamber at the junction of said housing members and having a double flanged edge, each of the flanges tapering from a minimum thickness at the edge of the flange to a maximum thickness at the base of the flange, the recesses in said housing members having a depth along the REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,324,701 Herman July 20, 1943 2,339,876 Phillips Mar. 7, 1944 2,343,320 Parker Mar. 7, 1944 2,387,598 Mercier Oct. 23, 1945 2,389,791 Lippincott Nov. 27, 1945 2,469,171 Mercier et al May 3, 1949 FOREIGN PATENTS Number Country Date 732,794 France Sept. 26, 1932 

